Transient behaviour of encapsulated enzyme reactor systems

Mathematical models are developed for the transient behaviour of encapsulated enzyme reactor systems such as the continuous stirred tank reactor (CSTR) and the packed bed tubular reactor. The rate processes taking place in the encapsulated enzyme bed are approximated by using a combined rate control model of enzyme reaction and membrane diffusion. The change in transient substrate concentration is obtained by using the developed rate expression in the material balance over the substrate as a function of time for the CSTR and as a function of time and position for the packed bed tubular reactor. The effects of various parameters such as the enzymic reaction rate constant, Michaelis constant, diffusional resistance of membranes, and Peclet number on the substrate concentration distribution, which varies with respect to operating time, are investigated. This study affords insight into the transient operating characteristics of the encapsulated enzyme reactor system. The results should be useful in understanding the start-up performance of the reactor systems and to control such reactor systems at desired operating conditions.     

Optimal resource allocation for transmission diversity in multi-radio access networks： a coevolutionary genetic algorithm approach

The next generation wireless communication systems aim at supporting enhanced diversified network access and data transmission abilities via the cooperative integration and unified management of various radio access technologies(RATs).The resource allocation is the core component leading the network system and mobile terminals to the service robustness and performance maximization.In this paper,a numeric optimization model for optimizing terminals’transmission power and allocated RAT bandwidth for maximizing system capacity is proposed with the focal consideration of the multi-radio transmission diversity for parallel transmission through multiple links from diferent RATs,and diferent terminal characteristics on RAT supports.Also,we design a centralized and periodic scheduling algorithm including an improved coevolutionary genetic algorithm for efciently solving the optimization problem.Simulation results demonstrate that our propose algorithm can distinctly enhance the system performance and improve the computational efciency.     

电力系统继电保护整定计算软件探析

介绍电力系统继电保护整定计算软件的相关问题,着重探讨了对该软件的改进措施.     

混凝土行业中基于JCS的海量数据协同模块的研究

随着国内预拌混凝土行业的发展,混凝土企业高层越来越意识到搅拌站信息化管理的必要性,各种混凝土搅拌站ERP软件在国内得到了迅速的发展,通过这种软件的信息化管理,后台数据库每天都会产生大量的生产数据。为了避免搅拌站之间的恶性竞争,混凝土行业协会和政府部门需要对某个区域乃至整个行业的搅拌站的生产运营情况有实时的了解,以便对其进行监管,最终促进行业的公平竞争。本文结合国内混凝土行业自身的特点,阐述了混凝土行业海量数据协同的总体构想和数学模型,之后从多维度论述了基于JCS多级缓存的海量数据协同模块的设计,最后,采用Socket的方式最终实现了Server端与Client端的一对多的数据通信。     

对网络内部终端安全管理的思考

随着信息化水平的不断提高,网络安全问题日益突出。如何建设维护一个稳定、安全的内部网络,已成为税务信息安全的重要问题。本文从网络终端入手,分析了网络安全管理中的现状及存在的问题,进而提出了解决问题的建议和对策。     

C语言编译密码方案的应用

随着计算机技术飞速发展,编程技术取得巨大进步,各种各样的程序为我们学习工作生活提供了很大方便,编程工具和语言类型也空前丰富。其中,C语言由于实现速度快,逻辑性强,在编程技术中占有重要地位,成为研究开发的重要工具,很多环境下非常便捷。本文从研究角度出发,以总结的方式,介绍在采用C语言编译密码方案并进行分析的过程,在应用中不断学习。     

基于Windows内核进程监控机制的研究与实现

互联网技术的不断发展对信息系统的安全提出了更高的要求,需要对系统提供更多方面的防护机制,而系统进程则是其中防范的一个方面。本文在Windows内核驱动程序理解的基础上,对系统进程监控技术进行了深入研究,采用事件触发的机制和技术,实现了对系统进程实时可靠的监控。     

粉煤灰作橡胶填料的影响因素

以钛酸酯偶联剂为表面处理荆，对粉煤灰进行表面处理，制得橡胶填料，测试了该填料对橡胶的补强作用。实验表明，表面改性后的粉煤灰对橡胶具有较好的补强作用。可完全替代碳酸钙、碳酸镁或陶土，产生较好的补强效果，用来替代部分发黑，可以减少发黑的用量，降低橡胶的成本。     

相转移催化合成癸二酸二甲酯

使用相转移催化剂BTEAC(氯化三乙基苄胺 )合成癸二酸二甲酯。条件为 :10g癸二酸 ,80mL甲醇 ,0 .5mL硫酸 ( 98% )和 0 .0 5gBTEAC。癸二酸二甲酯产率达到 90 .4 %     

Characterization of catalysts and membrane in DMFC lifetime testing

The lifetime and performance of a direct methanol fuel cell (DMFC) were investigated to understand the correlation between the structure of catalysts/membrane and cell performance versus time. The cell polarization and performance curves were obtained during the DMFC operation with the time. The catalysts and Nafion^® membrane of the membrane electrode assembly (MEA) from the lifetime test were comprehensively examined by XRD, HRTEM, FTIR and Raman spectroscopy techniques. The results revealed that there was significant performance degradation during the first 200 h operation; while the degradation was slowing down between 200 and 704 h operation. The degradation became worse after 1002 h operation. The increases of the catalyst particle size from both anode and cathode catalysts were observed after the DMFC lifetime test. The changes of microstructure, surface composition, the interfacial structure of the MEA, and the aging of Nafion^® under the DMFC lifetime tests were also observed.